Dynamo-electric machine



(No Model.)

G. BAEHR. DYNAMO ELECTRIC MACHINE.

No. 486,524. Patented Nov. 22, 1892.

f I i z ATTORNEY.

*UNITED STATES PATENT OFFICE."

GEORGE BAEHR, Oli BROOKLYN, NEW YORK.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 486,524, dated November 22, 1892.

Application filed December 18, 1891- gerial No. 415,452. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE BAEHR, a citizen of the United States, residing in Brooklyn, count-y of Kings, and State of New York, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

This invention relates to dynamo-electric machines and motors, and has special reference to the construction of the field-magnet, armature, and commutator. The object of the field-magnet construction is to prevent the stoppage of the machine in case a portion of the field-magnet coils should be burned out or otherwise destroyed. The object of the armature and commutator construction is to bring the two as closely together as possible and make the machine more compact and to provide a simple way of supporting the armature upon the shaft.

The invention will now be described in detail in reference to the accompanying drawings, in which- Figure l is a perspective View of the machine; Fig..2, a side elevation, and Figs. 3 and 4 views of the opposite sides of the armature and commutator.

AA represent two castings which are sub stantially fac-similes of each other, each being provided with pole-pieces a b, connected by a piece 0, forming the core of two coils. (Represented by D D.) The cores at the middle are enlarged to provide a bearing for the armature-shaft, as will be hereinafter described. These castings are placed together upon a base face to face, a small space a I) being left between them. The direction of the current through the coils is such that the parts of the pole-pieces adjacent to each other are of like polarity. Therefore the two magnetic circuits act together and in the same direction upon the armature. The coils of these two castings may be connected in series with each other or in multiple and the machine be equally as efficient; but if they are connected in multiple, and this I prefer, should one of the coils be burned out or short-circuited, so that the magnet of which it formed a part became deenergized, the circuit would still be continuous through the other magnet and the lines of force produced by it would still act upon the armature independent of the destroyed magnet and would pass through the armature in preference to the injured side of the fieldmagnet, because the air-gap between the two castings is made a trifle greater than the air-, gap between the faces of the poles and the armature-core. Another advantage arising from this construction of field-magnet is that any imperfections in the iron of one of the castings will not affect the circuit through the other casting. The total magnetic system is therefore more flexible and reliable than it is when entire. 1f the machine is compound wound, the series coil may be placed upon one side and the shunt-coil upon the other. Then if the series coil becomes destroyed the machine will continue to run as an ordinary shunt-dynamo. In case of damage to one of the coils it is obvious that the machine will lose some of its efficiencythat is, about twenty per cent.out the point is it will not stop. The machine may be either bipolar or multipolar and still act in the same manner as described.

The armature B is a Pacinotti ring supported upon the shaft by the cylindrical block 0 of fiber or other insulating material. This block serves as a spider and the armature is secured to it by means of radial screws 17', which pass through the lugs of the ring and into the block.

The commutator is formed of plugs d, having a threaded body, portions of which pass through the block of insulating material C and project slightly on each side. One end of the plug has a broad fiat head 01', against which the contact devices bear, and the other end has a slot to receive a screw-driver for working the plug into place. The ends of the coils are soldered or otherwise secured to the rear ends of the plugs, as shown in Fig. 4. A space is left between the heads of the adjacent plugs, so that they are perfectly insulated from each other. The contact device is a carbon pencil set at right angles to the face of the plugs in holders D, located on each side of one of the field-cores and supported on brass arms D It will be seen from the construction of this commutator that the armature and commutator stand in the same plane and that the commutator adds nothing to the width of the machine. The armatureshaft has its bearings in the iron portion of the field-magnets located between the parts 2. The combination, with an armature, of

of the coils. a disk or spider supporting the same, plugs Having thus described my invention, 1 of metal being inserted in the disk or spider claim with their ends exposed on both faces of the 5 1. In a dynamo-electric machine, the comdisk or spider, one end serving as a contact- 20 bination, with a rin g-arm at u re, of a field-inagsurface for the brushes and the other end hav net on each side thereof, each magnet coning attached to it the ends of coils on the arsisting of a vertical core wound with two coils, mature, substantially as described.

a space being left between them for the ar- In witness whereof I have hereunto signed IO mature-shaft bearings,pole-pieces projecting my name in the presence of two subscribing z 5 from each end of the cores and surrounding witnesses.

the side and periphery of the armature, pole- GEORGE BAEI-IR. pieces of like sign being opposite each other, Vitnesses: and the coils of the respective magnets being WM. A. ROSENBAUM,

r 5 in separate circuits,substantial1y as described. FRANK S. OBER. 

